Boring head



May 16, 1944.

r N. R. ELLIOTT BORING HEAD Filed June 25, 1940 4 Sheets-Sheet 1 INVENTOR NHTHHN/EL R ELL/0T7 .-1 TfOR/VE Y,

y 1944- N. R. ELLIOTT 2,349,033

BORING HEAD Filed June 25, 1940' 4 Sheets-Sheet 2 m mh m m m m WW M m mu w \z m 1. f/ m m 2 x 1:

May 16, 1944. N. R. ELLIOTT 2,349,033

BORING HEAD ,F'iled June 25, 1940 4 Sheets-Sheet 3 jfi /4 INVENTOR A/nT/m/w EL R. ELL/0T7 347mm; Y

May 16, 1944.

N. R. ELLIOTT I B ORING HEAD Filed June 25/ 1940 4,Sheets-Sheet 4 IIIIlllII/IIJ ,I'IIIIIA III I 4 LL INVENTOR By NATHAN/EL RELL/OTT .4 T70R25? Patented May 16, 1944 UNITED STATES PATENT OFFICE 1- Claim;

The invention relates to-a method and means for the installation of pipesand the'likein' the ground wherein a pipe-receiving bore is provided by and behind a head which is forced through the ground to displace and laterally compact the earth to provide the bore.

The general object of the invention is to provide an improved and particularly effective apparatus of the character described;

A more specific object is to provide a particularly eifective boring head for the apparatus;

Another object is toprovide an improved driving means for boring heads of the present type.

A further object is to provide an improved means for installing a flexible pipe or conduit in a ground bore provided'with the apparatus.

A further object is to provide an improved and particularly effective thrust block for mounting on a rod or pipe or the like for theapplication therethrough of a longitudinal push or pull'effort on the pipe.

Yet another object is to provide a particularly simple and compact device for gripping the for- Ward end of a pipe of copper or'other relatively soft material for its pulling through an earth bore.

An addedobject is to provide a pipe-installing apparatus which is particularly ada'ptedandarranged for its pneumatic operation.

The invention possesses other objects and features of advantage, some of whichiwith the foregoing will be set forth or be apparent inthe following description of typical embodiments thereof, and in the accompanying drawings, in which,

Figure 1 isa fragmentary sectional elevation showing an application of thepresentapparatus to provide a bore for the return'pulling of a flexiole pipe therethrough.

Figure 2 isa sectional elevation illustrating the manner of installing a flexible pipe in the bore.

Figure 3 illustrates one manner of installing a rigid pipe in a bore provided therefor.

Figure 4 is a fragmentaryside View of a boring head shown in Figure 1, portions of the fragments being shown in axial section.

Figure 5 is a front end view of thehead.

Figure 6 is a side elevation of an intermediate element of the head.

Figures 7 and 8 and 9 are cross-section's'taken respectively at the lines 1! and 88 and 9"9 of Figure 6.

Figure 10 is a cross-sectiontaken generally at the line. Ill-l0 in Figure 4'.

Figure 11 is an enlarged side elevation of a mounted impact block assembly which is shown in Figures 1 to 3', portions of the structure being shown in axial section.

Figure 1'2is an end'view of the block assembly shown inFigure 11.

Figure-13 is an enlarged elevation showing a means for attaching a flexible pipe to a pull rod of" the apparatus; as in Figure 2.

Figure 14 is an axial section through the arrangement of Fi'gure13'.

Figure 15is a sectional elevation taken through the ground end disclosing a modification of the apparatus utilizing'this'form of the boring head.

Figure 16 is an enlarged elevation of the boring head'shown in Figure 15;

Figure 17 is an axial section taken at l'L-l I in-Figure 16.

Figure 18 is an enlarged elevation of a-pneumatically operated'device for maintaining pressure behind the boring'hea'd of Figures 15 to 17.

Figure l9isa' crossesectionat l9!!l'in Figure 16.

The present-device is particularly designedfor a-subsurfa'ce installation of smaller pipes such as surfacepipes'for water and gas; and ab'ore for the installation'of such pipes is provided by pushing a boring head through' the ground. from one opening to another; As'a' boring head of my invention is pushedth'rough the ground, it is arranged to displace the ground laterally of its tapered working portion to compress the earth about the bore provided; inthis manner, no earth need be removed and the'compacted bore walls frequently stay'in that condition while a pipe is b'ein'g'moved' through the bore. It is to be understood, therefore, that the expression boringhead as hereinused applies to adisplacement head as Well as to a drilling head.

As shown in Figures 1 and 2, tl'ie'presentapparatus is'appliediin installing a-flexible pipe 2! of copper alloy or the like to extend between ground'holes' or openings 22 and 23. For providing a pipe-receiving bore 24, a boring head 25 is mounted at' the end of a push rod 26 by which-thehead'is pushed through the ground from the'opening 23 120 the opening 22; The rod I 26 is preferably madein mutuallydetachable secp'rocessbeing reversed when the rod is'-withdrawn. Thenecessaryforce for driving the head through the ground is applied to the rod portion which extends in the hole 23, the application of such force being made through a push block 27 which is arranged for mounting on the free rod extremity in the hole 23 and may be readily shifted to a successive rod section.

The driving force against the block 27 may be variously supplied, as by a jack or a hammer. Particularly in harder ground which permits the driving of a boring head and its push-rod therethrough, the use of a jack or a sledge hammer to impel the assembly may not be entirely satisfactory, and I prefer to utilize a pneumatic hammer 28 for the purpose. As shown in Figure l, the hammer 28 is of a type which is provided with a handle 23 at one side for its hand support.

to apply its reciprocable working head 33 against the block 21 for applying hammer blows to the rod in rapid succession, the hammer receiving compressed air for its actuation through a hose 3|.

It will now be noted that for installing the flexible pipe 2 I, said pipe may be drawn into the completed bore 24 by attaching its end to the forward end of the rod 26 extending into the ground opening 22', by means of a suitable coupling 32, whereby the rod 26 now becomes a pull rod. Since the pipe 2| is to be drawn through the completed bore 24 as the rod 26 is withdrawn therethrough, the rod movement may usually be considerably faster than when the bore was being provided. I therefore prefer to use a mechanical jack 33 or some other device which may be operated to withdraw the rod at a faster rate than the pneumatic hammer could do it,.

introduced into the bore is designed to insure.

a ready movement of the forward pipe end through the bore by reason of the action of the head to restore and/or maintain the compacted condition of the bore wall ahead of the pipe. It

is to be particularly noted that the present method of compacting the earth to provide a pipe-receiving bore insures against ground cavities along the pipe, since the compacted earth will subsequently expand to close the bore about the pipe and so not weaken the support of the ground above it, as may occur if the displaced earth has been removed as in providing a pipereceiving bore by drilling.

In Figure 3 I have illustrated the installation of a straight and inflexible pipe 2| in a bore 24 provided between ground openings 22 and 23. In this case, a diametrically larger head 25' is shown in use for installing the pipe 2| than was used in providing the bore 24, thisdevice, in effect, providing the pipe-receiving bore in two stages rather than initially providing it at full required size, as might be difficult for larger pipes or in hard-packed soil, and being utilized with flexible pipes as well. i

Referring now to Figures 4 to 10, it will be noted that the boring head 25 comprises a tapered nose portion 34, an intermediate portion 35 provided with a spiral external thread 31 and a rear portion 36; for reasons which will hereinafter be brought out, the head portions 34 and 35 and 36 are provided as separate elements for a unitary assembly.

The exterior spiral thread 31 of the section 35 preferably has a pitch which is uniform from its forward end to an intermediate point from which it progressively decreases toward its rear end, this section and the nose section 34 being arranged to rotate together as the head progresses through the earth. The section 35 is particularly shown asif formed by torsionally twisting a bar of triangular cross-section with its edges providing the three threads 31 having their sides making an angle of one hundred twenty degrees with each other, said edges being ground off in planes substantially tangent to the outline cylinder of the head.

As particularly shown, the nose section 34 has its point shaped somewhat as a star-drill, and at its rear end is provided with a threaded axial extension 38 for engagement in a complementarily threaded axial socket at the forward end of the section 35, a set screw 39 being operative in the section 35 against the mounted extension 38 of the nose section 34 for releasably locking said. sections together. In this manner, nose piece sections 34 of various designs may be provided and utilized for work in different earth compositions and formations.

A swivel connection is provided between the head sections 35 and 35. AS particularly illustrated, the element 36 is provided with an intermediately stepped axial bore 4|, having larger and smaller portions 42 and 43 extending from a shoulder 44. The bore portion 42 extends from the rear end of the section 36, and the bore portion 43 rotatably receives a swivel pin 45 therethrough to extend forwardly from the section 36. A forward end portion 46 of the swivel pin 45 is reduced and threaded for its limiting engagement as a stud bolt in a complementarily threaded socket provided in the opposed end of the section 35. A set screw 48 is preferably mounted in the section 35 to engage the pin portion 46 for fixing the swivel pin to the section. The rearward end portion of the pin 45 is externally threaded to mount a swivel head member 49 opposite the shoulder 44, whereby to secure the section 36 to the section 35 in swivelled relation. As shown, the member 49 comprises a nut, and is fixed in place on the pin after it has been installed.

Thrust bearings are provided between the forward end section 36 and the opposed end of the section 35; as shown, bearing rings 52 of any suitable composition and form are engaged about the pin 45 to provide an anti-friction hearing between the opposed ends of the connected sections. In the present structure, the rings 52 have the same external diameter as the adjacent cylindric portion of the section 36, and are enclosed in a guard sleeve 53 which extends rearwardly and integrally from a centrally perforated disc 54 which is mounted between the rings 52 and the opposed end of the section 35. As shown, the disc 54 is locked between the rear and sides of the section 35 and the shoulder at the base of the threaded portion 46 of the swivel pin whereby the sleeve comprises part of the section 35.

It will be understood that the described swivel connection between the head sections 35 and 36 provides for a rotation of the sections 34 and 35 together as the head is pushed through the ground, such rotationbeing caused by the action of the threads 3.! in the bore being provided.

When the head is pushed or pulled forwardly through the ground, as 'inFigure 1,, the bearing rings 52 transmit the effort between the portions 35 and 35. If the head is to be backed out of the bore, the effort willbe transmitted from the section 36 to the section- 35 at the bearing provided between the shoulder 44 and the swivel pin head49.

In the use of the head 25, it will generally be preferable that the head portion 36 and rod 26 do not rotate in the bore provided by the head. While friction may generally be depended on to prevent such a rotation, the portion 36 ispreferably provided with a series of radial fins 55 extending axially of the portion for likedis= tances therefrom. The fins 55, together with the relatively long and narrow head structure are of material aid in guiding and directing the boring head in a straight line in which it is orig.- inally started.

A member 56 is threadedly engaged in the outed end of the bore portion 32 in the section 35 beyond the member 59, and is provided with a threaded axial bore 51 haVlllg the same size and thread pitch as the nose-mounting sockets at the forward end of the section 35; It willnow be noted that the rod sectionsare each provided with threaded studs at one end and complementary sockets at the other, and thatsaid studs are arranged for threaded engagement in the bore 51 or engagement in the threaded socket in the forward end of the portion 35; in this manner the head may be secured to a push rod 26 in the relations shown in Figures 1 and z respectively, it being understood that the nose-section 34 would not be used in drawing a pipe through a previousl provided bore therefor.

Referring to the spirally threaded head section 35, it will be noted that the forward portion of its thread will effect its threaded and rotative engagement in a bore being formed by the forward progress of the head, and that the rearward threaded portion of decreasing pitch will operate to wedgedly smooth the bore sides so that the bore is truly cylindricalbehind'said section. As the head advances in the bore, the fins 55, which have tapered front end portions wedged ly provide longitudinal grooves or flutes along the bore sides. It will thus be understood that the bore 24 is provided entirely by a: compression of the displaced material laterall thereof, and that the bore will thereafter tend to contract about an installed pipe.

The push block 27 through which alongitudi nal pushing or pulling force may be exerted on the rod 25, must be of such a structure that it grips an engaged rod section against its longitudinal movement therealon-g. By particular reference to Figures 11 and 12, it will be noted that the present member 21 essentially comprises a pair of V-blocks El and 62 having pipe-gripping faces 63 and M respectively which are provided with teeth 65 extending circumferentially of a rodwhich they are to engage. The blocks El and '62 are connected by a U-bolt 56 which engages across the outer face of the block 6| at a bearing socket provided therefor, and has its legs straddling the block BI and engaged freely through lateral cars 61 of the block 62, the extremities of said legs being threaded to mount wing nuts 68 upon the ears 61.

For installing the assembly 21, the blocks 6i and 62 are placed against opposite sidesof the rod portion with the plane of the U-bolt-Bfi substantially perpendicular to therodaxisandthe nuts '68 are applied and screwed up on the bolt legs until'moderately tight. If, now, either block is urged axially of the rod, a movement thereof relative to the other block will tend to swing the U-bolt 63 away from a perpendicular relation to the rod and so force the teeth 65 of both blocks into the rod by shortening the efiective distance between the blocks; The aforesaid action is illustrated in Figure 11' by a dotted line showing of the block BI and the U-bolt in original positions before the force is applied to an end Gil of the block 6!. The block end 59 comprises a fiat working face against which impact and/or pressure are to be applied for locking the assembly 21 to the rod and thereaftereifecting its longitudinal movement.

The teeth 65 for the block Bl comprise continuous ridges extending across the angularly related working faces of the block, and are preferably provided by a removable facing member H which fits within the block V groove. The teeth of the member H slope forwardly with respect to the locking and driving movement for the block '61, and a stop ridge I2 is provided at the rear end of the block groove for engaging the rear end of the member, the member being removable and replaceable. The teeth @Efor the block 62 are provided on the inner face of a facing member H which is welded Or otherwise secured in the V groove of its block. The facing members H and 13 may be conveniently shaped of pieces of highly tempered files to insure a greater hardness for their teeth 6a than that of the rod or pipe to be gripped, this type of facing member being particularly illustrated.

For loosening the push block unitil on the rod 26, it is merely necessary to move the block 6| back on the block 62 to dispose the U-bolt '66 more nearly perpendicular to the rod axis. When the block is loosened it may be slid along the pipe, or the wing nuts 68 may be removed if complete disassembly is desired. When, as at present, the rod 26 is formed without enlargements at the section joints, the loosened block may be slid along from section to section as the rod is increased or decreased in length.

Recalling the general softness of copper and lead alloy tubes or pipes which are frequently installed in the ground in lieu of iron pipes because of their resistance to corrosion and very much longer life, means are provided for gripping an end of such tubing for longitudinally pulling it through an only slightly larger bore in the earth. The flexible pipe 2! of Figures 1 and 2 is shown as provided on a spool '15 from which it may be unrolled as it is pulled through a bore 24. In general terms, the coupling 32 comprises a device which is expended within the leading pipe end portion to taper and back the same within and behind a ring or sleeve 78 in an arrangement in which the expanding device is attached to the rod 25 for pulling the pipe.

As particularly brought out in Figure 14, an initially one-piece cylindrical block of uniform cross-section is provided with a stepped axial bore having its smaller bore portion tapered from its inner end and provided with threads with a uniform pitch, the larger and unthreaded bore portion 78 being of uniform cross-section and having a greater diameter than the threadbase diameter of the bore portion 18. The original diameter of the block is slightly less than the normal bore diameter for the pipe 26, and the sides of the block may be provided with facing members 19 of brass or other moderately soft material. At the end thereof from which the bore portion I8 extends, a relatively short block portion is externally threaded for engagement in a complementarily threaded counterbore provided at one end of a ring member 88 which has an external diameter approximating that of the pipe and is slidable in the sleeve I6. The block formed as described is longitudinally split to provide complementary section 8i, and said block may be unitarily referred to as an expansion block 8I8I.

With the block sections 8I held together in mutual opposition, they are arranged to be threadedly engaged in the counterbore of the ring 88 and inserted in the pipe end with the threaded end of the ring 88 close to or adjacent the pipe extremity. With the expansion block 8I8l installed as described, the point of a lag bolt 82 is inserted through the ring 88 and bore portion 78 for engaging the threaded bore portion TI and having the same thread form and pitch as provided in the latter bore portion is screwed into said portion. The efiect of screwing the lag bolt 82 into the expansion block 8I-8I is to angularly separate the sections 8| about their mutual anchorage in the ring 88 to stretch the pipe within and beyond the sleeve I6 which has been mounted on the pipe end to extend for substantially half of the length of the block 8I8I. In this manner, the screwing-in of the bolt 82 may spread the pipe behind the sleeve 16 as may be required to firmly and wedgedly grip the pipe between the block sections BI and the sleeve I6, particularly at the rear end of the latter.

A bearing ring 83 encircles the shank of the bolt 82 between its head 82 and inturned flange 84' of a coupling sleeve 64 which freely receives the bolt head 82' for its turning therein as by a socket wrench (not shown), the other end of the sleeve 64 being arranged to threadedly receive a connector block 86 which has a threaded extension 85' for connection with the rear nozzle member 36 as shown in Figure 2 or for use in direct connection with the rod 26. The arrangement is understood to provide for the required gripping Of a pipe 2| in a positive manner and by a means which is no larger than the bore into which the pipe is arranged to be drawn. A further feature is the swivel connection provided between the bolt head 82 and the flange 84' of the coupling sleeve 84, except when a bolt is screwed into a limiting degree to positively clamp the bearing ring 83 between the head and flange.

In the embodiment of the invention shown in Figures -19, a boring head 8-6 is provided for driving through the ground, as between holes M and 88, by means of a pneumatic hammer 89 mounted within it. The hammer 89 has its body 9| slidably and rotatably engaged within a complementary bore 92 provided in the head 86. The head 86 has a tapered nose portion and is provided on its exterior with spiral threads 93 which have a uniform pitch at the forward portion of the head and a progressively decreasing pitch for the balance of their length. The action of the threads 93 as the head 86 is pushed forwardly to provide a bore is similar to that of the head of the previously described embodiment. At its closed forward end, the cavity 92 of the boring head is more or less reduced and provides a seat for impact discs 84 of fiber, leather, or the like against which the working head 95 of the hammer 89 is arranged to strike.

The pneumatic hammer 89 is of a usual type of structure and includes a piston 96 repetitively operative within a cylinder 91 under the influence of compressed air to strike a rod 98 which carries the head 95 and is freely slidable and rotatable in an axial guide bore provided at the head end of the cylinder 91. It will be understood that the position of the piston controls the valves of the hammer through which the operating air is supplied to the cylinder. The maximum working stroke for the hammer head would be as required for driving the boring head, and the hammer is fixed to the forward end of a pipe 99, which pipe is arranged to supply the operating air to the hammer and also function as a' push or pull rod therefor.

The pipe 99 is connected to the hammer 89 at a reduced and tubular rear extension I8I of its body 9| which has a radial flange I82 at said extremity. A screw I83 or the like is mounted at a rear point of the rotary boring head 86 and extends into the space between the body 9! and the flange I82 as a stop means to provide for a withdrawing of the boring head with the hammer, while permitting the operation of the hammer within the boring head to drive the same. It will be understood that the necessary swivel connection between the rotary boring head 86 and the push pipe 99 is pro vided by the rotative engagement of the impact rod 98 of the hammer 89 in the forward cylinder end.

Means are provided for constantly urging a forward movement of the hammer and boring head, said means being pneumatic. As particularly illustrated in Figures 15 and 18, the rear end of the pipe 98 threadedly mounts a thrust block I84 which is provided with a seat socket I85 in the axial line of the pipe and a duct I86 for connecting the pipe passage with a hose I81 suitably connected to the block at a coupling I89.

A pneumatic jack I89 is mounted in the hole 81 with its piston rod 8 extended in the axial line of the pipe 99 and seated in the socket I85 of the block I84, the rear end of the jack being seated against the opposite side of the hole 81 or otherwise held. Compressed air is supplied to the rear end of the jack cylinder I I I behind the piston I I2 through a pipe H3 having a relief valve II4 for manual opening interposed therein. The hose I81 and the pipe I I3 are arranged to receive compressed air for operating the hammer and jack respectively through a normally closed air distributing valve II5 which receives air through a hose I I6 which is connected with a suitable source (not shown) of compressed air.

As shown, the distributing valve I I5 is conveniently mounted on the jack I89 and is provided with a handle extension H1 at the free end of which the hose I I6 is connected. A valve control lever I I8 extends opposite the handle I I1 whereby an operator gripping the handle may rock the lever to open the valve and simultaneously effect the operation of the hammer and jack, under the same air pressure. When a full working stroke of the jack piston I I2 has been completed, the relief valve I I4 is opened to permit a return of the piston I I2 and its rod I I8 to their starting positions, and a new section is inserted in the pipe 99 at the thrust block. The closing of the valve Ill and the opening of the valve II5 then permits the drivingof the boring head 86 for the length of the inserted pipe section.

While it will not generally be necessary to withdraw the head 86 through the bore provided by it, this may be accomplished by hand or by reversing the pneumatic jack I89 to act against the installed pipe 99; in the latter case the push block assembly 21 might be utilized on the pipe in using the pneumatic jack I09 or a mechanical jack 33 to withdraw the pipe and the boring head assembly.

From the foregoing description taken in connection with the accompanying drawings, the advantages of the construction and operation of the present device will be readily understood by those skilled in the art to which this invention appertains. While I have described the features and principles of operation of apparatus which I now consider to comprise preferred embodiments of my invention, I desire to have it understood that the showing is primarily illustrative, and that such changes may be made, when desired, as fall within the scope of the following claim.

What I claim is:

A ground-piercing apparatus comprising a boring head for axial propulsion through the earth to provide a bore by earth displacement laterally 5, thereof, and a helical thread on said head having 

